Sea shell. X-ray of the shell of a sea snail. Shells are secreted by gastropod molluscs for protection. The animal can withdraw entirely into its shell when threatened. The chambers at the apex are the oldest,and successively larger whorls are added as the animal grows. The central pillar is called the columella. The calcium-rich shell is secreted from the mantle,a soft covering formed from the body wall | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Gustoimages |
Taille de l’image : | 3934 px × 4590 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |